Perfuming compositions

Abstract

Disclosed are fragrance compositions comprising ethyl cyclohexanoate.

Description

[0001] This disclosure relates to fragrance compositions and to a method of enhancing them.

[0002] Fragrance compositions are usually blends of volatile individual ingredients, both natural and synthetic, carefully blended by skilled perfumers to bring out an overall desired hedonic character. The individual ingredients are selected to add to this particular desired character.

[0003] A very common class of fragrance ingredient is the ester. Esters are found in the essential oils of many plants and are known for their sweet, fruity odor. As a result, they are a popular choice for fragrance compositions. Typical examples of popular fragrance esters include benzyl acetate, bornyl acetate (1,7,7-trimethylbicyclo[2.2.1]heptan-2-yl acetate), 2-tert-butyl-cyclohexylacetate (Agrumex ™< ) and octahydro-4,7-methano-3aH-indene-3a-carboxylic acid, ethyl ester (Fruitate ™< ), and 1,3-cyclohexadiene-1-carboxylic acid, 2,6,6-trimethyl-, ethyl ester (Ethyl Safranate ™< ). All of these are known to have pleasant, desirable odors.

[0004] It has now been found that the addition of a particular ingredient can enhance the desirable characteristics of ester-containing fragrance compositions. There is therefore provided a fragrance composition comprising a blend of fragrance ingredients, at least one of which ingredients is an ester, the composition additionally comprising 0.0001 to 0.1% by weight of ethyl cyclohexanoate.

[0005] Ethyl cyclohexanoate, sometimes referred to as ethyl cyclohexyl carboxylate (CAS 3289-28-9), has an odour described as "fruity, cheesy, winey" in the database of the Good Scents Company, a well-known flavour and fragrance resource. It is known to occur in various natural oils, for example, in virgin olive oil (see, for example, Reiners et al, J. Agric. Food Chem. 1998, 46, 2754-2763) and rum (see Franitza et al, J. Agric. Food Chem. 2016, 64, 637-645). However, although known and characterized, it has never been produced as a commercial fragrance material and there is no disclosure of fragrance compositions comprising said compound.

[0006] It has been found uniquely to enhance the odour characteristics of esters; it has no perceptibly effect on other class of fragrance ingredients, such as alcohols, ketones or aldehydes.

[0007] Moreover, it has been found that, in order to achieve this desirable effect, the proportion of ethyl cyclohexanoate must be used within strict limits - too little, and there will be no enhancing effect, too much and there will be an undesirable "cheesy" odor. The ethyl cyclohexanoate should therefore be used at concentrations 0.0001 to 0.1% by weight, , which includes 0.0001 - 0.02% by weight (e.g., 0.0005% or 0.001% or 0.05% by weight), based on the fragrance composition. However the amounts of ethyl cyclohexanoate present in a fragrance composition may vary, depending on the other fragrance ingredients present. In a further aspect of the present invention, the ratio of ethyl cyclohexanoate to ester should be used within strict limits to avoid that the undesirable "cheesy" odor will be recognized. The ethyl cyclohexanoate should therefore be used at a weight ratio of from 1 : 10'000'000 to 1 : 1'000 (which includes 1 : 5'000'000 and 1 : 1'000'000 to 1 : 1'000) of the ester component of the fragrance composition (ethyl cyclohexanoate : ester(s)), and wherein the ester is a compound of formula (I) having a molecular weight of 130 to 300 and wherein i) R 1< is selected from methyl, ethyl, C 3 to C 6 alkyl, and C 2 to C 6 alkenyl (for example, hexenyl, prop-2-enyl), and R 2< is a hydrocarbon radical containing 5 to 10 C-atoms (for example 5, 6, 7, 8, 9, or 10 C-atoms), optionally comprising one, two, or three functional groups selected from -OH (alcohol), -C(O) - (carbonyl), and ether (-O-); or ii) R 1< is a hydrocarbon radical containing 5 to 14 C-atoms (for example 5, 6, 7, 8, 9, 10 or 11 C-atoms), optionally comprising one, two, or three functional groups selected from - OH (alcohol), -C(O) - (carbonyl), and ether (-O-), and R 2< is selected from methyl, ethyl, C 3 to C 6 alkyl, or C 2 to C 6 alkenyl (for example, hexenyl, prop-2-enyl).

[0008] There is also provided a method of enhancing the fragrance quality of a fragrance composition containing at least one ester, comprising the addition thereto 0.0001 to 0.1% by weight (e.g. 0.0005, 0.001, 0.01, 0.02, 0.05 % by weight) of ethyl cyclohexanoate.

[0009] In a further embodiment there is provided a method of enhancing the odor characteristics of esters, in particular of esters providing fruity odor characteristics. By "enhancing the fruity character" is meant that the addition of ethyl cyclohaxane-carboxylated results odor characteristics which are preserved as more juiciness and more natural overall character. Thus there is provided a method of enhancing the fruity characteristics of esters of formula (I) as herein defined, comprising the step of adding ethyl cyclohexanecarboxylate to a flavor or fragrance composition. For example it enhances the impression of juiciness and ripe fruits such as grapefruit, mango, citrus, orange and the like.

[0010] By "enhancing" is meant that the hedonic qualities of the ester, and of the fragrance composition in which it is incorporated, are improved from the point of view of being not only more pleasant, but also more balanced, more natural and / or more intense. The overall hedonic effect is much improved and more desirable, and in general more preferred compared to compositions which are free of ethyl cyclohexanoate.

[0011] By "ester" is meant a compound of formula (I) having a molecular weight of 130 to 300 (e.g. 130 to 250) and wherein i) R 1< is selected from methyl, ethyl, C 3 to C 6 alkyl, and C 2 to C 6 alkenyl (for example, hexenyl, prop-2-enyl), and R 2< is a hydrocarbon radical containing 5 to 10 C-atoms (for example 5, 6, 7, 8, 9, or 10 C-atoms) , optionally comprising one, two, or three functional groups selected from -OH (alcohol), -C(O) - (carbonyl), and ether (-O-); or ii) R 1< is a hydrocarbon radical containing 5 to 14 C-atoms (for example 5, 6, 7, 8, 9, 10 or 11 C-atoms) , optionally comprising one, two, or three functional groups selected from - OH (alcohol), -C(O) - (carbonyl), and ether (-O-), and R 2< is selected from methyl, ethyl, C 3 to C 6 alkyl, or C 2 to C 6 alkenyl (for example, hexenyl, prop-2-enyl).

[0012] As used in relation to compounds of formula (I) unless otherwise indicated "hydrocarbon radical" includes linear, branched, mono-, bi- or tri-cyclic alkyl, linear, branched, mono-, bi- or tricyclic alkenyl (comprising one or more double bonds), and aryl, wherein the ring (such as cyclic alkyl, cyclic alkenyl, aryl) is optionally substituted with alkyl.

[0013] Non-limiting examples of esters are compounds of formula (I) wherein either R 1< or R 2< is not alkyl.

[0014] Further specific examples of known esters according to formula (I) are: 4-(tert-butyl)cyclohexyl acetate; ethyl 2-methylpentanoate (Manzanate); hexyl salicylate; methyl 3-oxo-2-pentylcyclopentaneacetate (Hedione); 2-tert-butyl-cyclohexylacetate (Agrumex ™< ); octahydro-4,7-methano-3aH-indene-3a-carboxylic acid, ethyl ester (Fruitate ™< ); and 1,3-cyclohexadiene-1-carboxylic acid, 2,6,6-trimethyl-, ethyl ester (Ethyl Safranate ™< ). Further specific esters according to formula (I) are methyl 2,4-dihydroxy-3,6-dimethylbenzoate (CAS 4707-47-5); allyl heptanoate (CAS 142-19-8); dimethyl benzyl carbinyl acetate (CAS 151-05-3); dimethyl benzyl carbinyl butyrate (CAS 10094-34-5); 3a,4,5,6,7,7a-hexahydro-1H-4,7-methanoinden-6-yl propionate (CAS 68912-13-0); and (Z)-hex-3-en-1-yl acetate (CAS 3681-71-8).

[0015] The esters may be synthetic ingredients or they may occur in natural fragrance oils. The individual esters present in a known natural fragrance oil can be found by reference to Journals commonly used by those skilled in the art such as "Perfume and Flavourist" or "Journal of Essential Oil Research", or listed in reference texts such as the book by S. Arctander, Perfume and Flavor Chemicals, 1969, Montclair, New Jersey, USA and more recently re-publisehd by Allured Publishing Corporation Illinois (1994).

[0016] A fragrance composition as hereinabove described may, in addition to at least one ester, contain any of the other natural or synthetic ingredients known to the art to be useful in fragrance compositions. Non-limiting examples of such compositions include essential oils and extracts, e.g. castoreum, costus root oil, oak moss absolute, geranium oil, tree moss absolute, basil oil, fruit oils, such as bergamot oil and mandarine oil, myrtle oil, palmarose oil, patchouli oil, petitgrain oil, jasmine oil, rose oil, sandalwood oil, wormwood oil, lavender oil and / or ylang-ylang oil; alcohols, e.g. cinnamic alcohol ((E)-3-phenylprop-2-en-1-ol); cis-3-hexenol ((Z)-hex-3-en-1-ol); citronellol (3,7-dimethyloct-6-en-1-ol); dihydro myrcenol (2,6-dimethyloct-7-en-2-ol); Ebanol ™< ((E)-3-methyl-5-(2,2,3-trimethylcyclopent-3-en-1-yl)pent-4-en-2-ol); eugenol (4-allyl-2-methoxyphenol); ethyl linalool ((E)-3,7-dimethylnona-1,6-dien-3-ol); farnesol ((2E,6Z)-3,7,11-trimethyldodeca-2,6,10-trien-1-ol); geraniol ((E)-3,7-dimethylocta-2,6-dien-1-ol); Super Muguet ™< ((E)-6-ethyl-3-methyloct-6-en-1-ol); linalool (3,7-dimethylocta-1,6-dien-3-ol); menthol (2-isopropyl-5-methylcyclohexanol); Nerol (3,7-dimethyl-2,6-octadien-1-ol); phenyl ethyl alcohol (2-phenylethanol); Rhodinol ™< (3,7-dimethyloct-6-en-1-ol); Sandalore ™< (3-methyl-5-(2,2,3-trimethylcyclopent-3-en-1-yl)pentan-2-ol); terpineol (2-(4-methylcyclohex-3-en-1-yl)propan-2-ol); or Timberol ™< (1-(2,2,6-trimethylcyclohexyl)hexan-3-ol); 2,4,7-trimethylocta-2,6-dien-1-ol, and / or [1-methyl-2(5-methyl hex-4-en-2-yl)cyclopropyl]-methanol; aldehydes and ketones, e.g. anisaldehyde (4-methoxybenzaldehyde); alpha amyl cinnamic aldehyde (2-benzylideneheptanal); Georgywood ™< (1-(1,2,8,8-tetramethyl-1,2,3,4,5,6,7,8-octahydronaphthalen-2-yl)ethanone); Hydroxycitronellal (7-hydroxy-3,7-dimethyloctanal); Iso E Super ®< (1-(2,3,8,8-tetramethyl-1,2,3,4,5,6,7,8-octahydronaphthalen-2-yl)ethanone); Isoraldeine ®< ((E)-3-methyl-4-(2,6,6-trimethylcyclohex-2-en-1-yl)but-3-en-2-one); 3-(4-isobutyl-2-methylphenyl)propanal; maltol; methyl cedryl ketone; methylionone; verbenone; and / or vanillin; ether and acetals, e.g. Ambrox ®< (3a,6,6,9a-tetramethyl-2,4,5,5a,7,8,9,9b-octahydro-1H-benzo[e][1]benzofuran); geranyl methyl ether ((2E)-1-methoxy-3,7-dimethylocta-2,6-diene); rose oxide (4-methyl-2-(2-methylprop-1-en-1-yl)tetrahydro-2H-pyran); and / or Spirambrene ®< (2',2',3,7,7-pentamethylspiro[bicyclo[4.1.0]heptane-2,5'-[1,3]dioxane]) ; macrocycles, e.g. Ambrettolide ((Z)-oxacycloheptadec-10-en-2-one); ethylene brassylate (1,4-dioxacycloheptadecane-5,17-dione); and / or Exaltolide ®< (16-oxacyclohexadecan-1-one); and heterocycles, e.g. isobutylquinoline (2-isobutylquinoline).

[0017] Fragrance composition comprising ethyl cyclohexanoate and at least one ester, as hereinabove described, may be used in a broad range of fragranced articles, for example, in any field of fine and functional perfumery, such as perfumes, air care products, household products, laundry products, body care products and cosmetics. The composition can be employed in widely varying amounts, depending upon the specific application and on the nature and quantity of other odorant ingredients. The proportion is typically from 0.1 to 20 weight percent of the application. In one embodiment, the composition of the present invention may be employed in a fabric softener or shampoo in an amount of from 0.2 to 1.5 weight per cent (e.g. 0.8 - 1 weight %). In another embodiment, the fragrance composition comprising ethyl cyclohexanoate and at least one ester may be used in fine perfumery in amounts of from 5 to 20 weight per cent (e.g. up to about 30 weight per cent). However, these values are given only by way of example, as the experienced perfumer may also achieve effects or may create novel accords with lower or higher concentrations.

[0018] Moreover it has been found, that the odor performance is enhanced when a fragranced article comprising a fragrance composition as hereinabove described, is diluted with water. Thus, there is provided as one specific embodiment, the use of a fragrance composition comprising ethyl cyclohexanoate and at least one ester, as hereinabove described, in rinse-off products, such as shampoo, and shower gel, but also in high dilutions in water, like hand wash fabric detergents (liquid or powder) or multi-purpose floor cleaners.

[0019] It was also observed that ethyl cyclohexanecarboxylate significantly reduces a perceived malodor, such as kitchen malodor, bathroom malodor, sweet malodor and the like. Thus one may cited as a further example air care products to which ethyl cyclohexanecarboxylate may by admixed.

[0020] The fragrance composition as described hereinabove may be employed in a consumer product base simply by directly mixing the fragrance composition with the consumer product base, or it may, in an earlier step, be entrapped with an entrapment material, for example, polymers, capsules, microcapsules and nanocapsules, liposomes, film formers, absorbents such as carbon or zeolites, cyclic oligosaccharides and mixtures thereof.

[0021] All percentages and ratios as used herein are by weight unless otherwise indicated.

[0022] The invention is now further described with reference to the following non-limiting examples. These examples are for the purpose of illustration only and it is understood that variations and modifications can be made by one skilled in the art.Example 1: Synthesis of ethyl cyclohexanoate

[0023] Cyclohexanecarboxylic acid (64 g, 0.50 mol) and p-toluenesulfonic acid (1.0 g, 0.01 mol) in cyclohexane (64 g) were heated to 73 °C. Ethanol (64 g, 1.39 mol) was added over 90 min and the reaction mixture was stirred at reflux for an additional 90 min while the aq. phase was gradually eliminated over time. After cooling the reaction mixture to r.t., the org. phase was washed with H 2 O, 4% aq. Na 2 CO 3 -solution and H 2 O. The org. phase was concentrated and distilled to yield 73 g (93%) of ethyl cyclohexanecarboxylate as a colorless oil.

[0024] 1< H NMR (CDCl 3 , 400 MHz): δ = 4.09 (q, J = 7.1 Hz, 2H), 2.25 (tt, J = 11.3, 3.7 Hz, 1H), 1.90-1.83 (m, 2H), 1.78-1.70 (m, 2H), 1.64-1.58 (m, 1H), 1.46-1.36 (m, 2H), 1.31-1.17 (m, 3H), 1.22 (t, J = 7.1 Hz, 3H) ppm.

[0025] 13< C-NMR (CDCl 3 , 100 MHz): δ = 176.0 (s), 59.9 (t), 43.2 (d), 29.0 (2t), 25.7 (t), 25.4 (2t), 14.2 (q) ppm.

[0026] MS (El, tR = 4.89 min): 156 (43, [M] +·< ), 128 (21), 115 (16), 111 (41), 110 (23), 101 (68), 88 (21), 83 (100), 82 (17), 81 (17), 73 (21), 68 (15), 67 (16), 55 (79), 54 (11), 41 (38), 39 (20), 29 (30), 27 (20).Example 2:

[0027] The following solutions were prepared. A) 0.1 weight % of ethyl cyclohexanoate in ethanol B) 10 weight % of fragrant ingredient in ethanol

[0028] The two alcoholic solutions above were mixt at a ratio of 1:1.

[0029] Both, solution B alone and the mixture of A+B was olfactively evaluated in a triangular test on a blotter in a randomized order. The trained panel was asked to describe the olfactory difference, if any. The results are summarized in Table 1 below.

[0030] As can be seen from the results above, the addition of ethyl cyclohexanoate to a fragrant ester results in a more pleasant, more balanced, more natural and / or more intense composition which is more preferred compared to the esters alone. On the other hand, such a benefit was not observed when ethyl cyclohexanoate was added to a fragrant aldehyde, ketone or alcohol.Example 3:

[0031] Ethyl cyclohexanoate (A) was evaluated on blotter in combination with several odorant esters as indicated at different concentrations. The results are shown in Table 2 below. Example 4: Fragrance accord suitable for shampoo

[0032] Compound / Ingredientparts by weight 1 / 1000Agrumex40Allyl Heptanoate25Benzyl Acetate20Citronellol20Cyclohexal24Delta Damascone1Dihydro Myrcenol50Dimethyl benzyl carbinyl acetate15Dimethyl benzyl carbinyl butyrate5Dipropylene Glycol (DPG)177Ethyl 2-Methylbutanoate7Evernyl (methyl 2,4-dihydroxy-3,6-dimethylbenzoate)8Fixolide (1-(3,5,5,6,8,8-hexamethyl-5,6,7,8-tetrahydro naphthalen-2-yl)ethan-1-one)30Florocyclene (3a,4,5,6,7,7a-hexahydro-1H-4,7-methanoinden-6-yl propionate20Galaxolide (4,6,6,7,8,8-hexamethyl-1,3,4,6,7,8-hexahydrocyclopenta[g]isochromene)120cis-3-Hexen-1-ol3(Z)-Hex-3-en-1-yl acetate32-Benzylideneoctanal50Beta lonone ((E)-4-(2,6,6-trimethylcyclohex-1-en-1-yl)but-3-en-2-one)60Iso E Super20Lilial (3-(4-(tert-butyl)phenyl)-2-methylpropanal)50Linalool30Manzanate3Orange oil60Peach Pure (γ-undecalactone)102-phenoxyethyl isobutyrate140Tricyclal (2,4-dimethylcyclohex-3-ene-1-carbaldehyde)6Ethyl cyclohexanoate (at a dilution as indicated in Table 3 below)3Total:1000

[0033] The fragrance accord comprising 29.6 weight % of esters according to formula (I) and a variable amount of ethyl cyclohexanoate (A) in DPG as indicated in Table 3, first column, was assessed by a trained panel neat (on a blotter), in a shampoo (fragrance accord @ 0.5 weight %), and in a shampoo (fragrance accord @ 0.5 weight %) diluted with water. The results are given in Table 3 below. Table 3:(A) [%]on blotterin shampoo2 ml shampoo in 50 ml water4.110.0Over ripe unpleasantOver ripe, sweaty animalic, unpleasantOver ripe, sweaty animalic, unpleasant, more lift, more intense, but unpleasant4.21.0more juicy more green more intenseintense juicy fruity apple , starts to cover over all perfume character, still likedintense juicy fruity apple , starts to cover over all perfume character, still liked4.30.1push green pineapple esters, more aggressivealready benefit, more natural, more juicy, more pleasant, more depth, more intensity, clear benefit, preferred to 4.2already benefit, more natural, more juicy, more pleasant, more depth, more intense, clear benefit, preferred to 4.24.40.01clear and good benefit, push juicyalready benefit, more natural, more juicy, more pleasant, more depth, more intense, clear benefit, more lift, more freshness, effect even more noticeablealready benefit, more natural, more juicy, more pleasant, more depth, more intense, clear benefit, more lift more freshness, effect even more noticeable, liked, preferred to 4.34.50.001more juicy already benefitalready benefit more natural more juicy more pleasantalready benefit, more natural, more juicy, more pleasant, rounder, less green aggressive, more consumer appeal, more natural

[0034] As can be seen from the summary of the olfactory description of the fragrance accord in Table 3 above, the positive effect of ethyl cyclohexanoate on esters is more effective than the findings with regard to alcohols, aldehydes and ketones taken alone, resulting in an hedonically more pleasant fragrance formulation.

Claims

1. A fragrance composition comprising 0.0001 to 0.1 weight % ethyl cyclohexanecarboxylate and at least one odorant ester, and wherein the weight ratio between ethyl cyclohexanecarboxylate and the at least one odorant ester is from 1 : 10'000'000 to 1 : 1'000 (ethyl cyclohexanecarboxylate : ester) and wherein the odorant ester is a compound of formula (I) having a molecular weight of 130 to 300 and wherein i) R1 is selected from methyl, ethyl, C3 to C6 alkyl, and C2 to C6 alkenyl, and R2 is a hydrocarbon radical containing 5-10 C-atoms, optionally comprising one, two, or three functional groups selected from -OH, -C(O), and -O-; or ii) R1 is a hydrocarbon radical containing 5 to 14 C-atoms , optionally comprising one, two, or three functional groups selected from -OH, -C(O), and -O-, and R2 is selected from methyl, ethyl, C3 to C6 alkyl, and C2 to C6 alkeny.

2. A fragrance composition according to claim 1 wherein the compound of formula (I) is selected from the group consisting of 4-(tert-butyl)cyclohexyl acetate; hexyl salicylate; ethyl 3-oxo-2-pentylcyclopentaneacetate; 2-tert-butyl-cyclohexylacetate; octahydro-4,7-methano-3aH-indene-3a-carboxylic acid, ethyl ester; 1,3-cyclohexadiene-1-carboxylic acid, 2,6,6-trimethyl-, ethyl ester; methyl 2,4-dihydroxy-3,6-dimethylbenzoate; allyl heptanoate; dimethyl benzyl carbinyl acetate; dimethyl benzyl carbinyl butyrate; ethyl 2-methylbutanoate; 3a,4,5,6,7,7a-hexahydro-1H-4,7-methanoinden-6-yl propionate; . (Z)-hex-3-en-1-yl acetate; benzyl acetate; bornyl acetate; linalyl acetate; 4-(tert-butyl)cyclohexyl acetate; and hexyle salicylate.

3. A fragrance composition comprising at least one ester of formula (I) as defined in claim 1 with an "enhanced" odor profile obtained by admixing thereto 0.0001 to 0.1 weight % ethyl cyclohexanecarboxylate.

4. A fragranced article comprising a fragrance composition as defined in one of the proceeding claims.

5. A method of enhancing the fruity characteristics of esters, comprising the step of adding 0.0001 to 0.1 weight % ethyl cyclohexanecarboxylate to a composition comprising at least one odorant ester, and wherein the weight ratio between ethyl cyclohexanecarboxylate and the at least one odorant ester is from 1 : 10'000'000 to 1 : 1'000 (ethyl cyclohexanecarboxylate : ester) and wherein the odorant ester is a compound of formula (I) having a molecular weight of 130 to 300 and wherein ii) R1 is selected from methyl, ethyl, C3 to C6 alkyl, and C2 to C6 alkenyl, and R2 is a hydrocarbon radical containing 5 to 10 C-atoms, optionally comprising one, two, or three functional groups selected from -OH, -C(O), and -O-; or ii) R1 is a hydrocarbon radical containing 5 to 14 C-atoms , optionally comprising one, two, or three functional groups selected from -OH, -C(O), and -O-, and R2 is selected from methyl, ethyl, C3 to C6 alkyl, and C2 to C6 alkeny.

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